This invention relates to hand-held tools such as electric drills and, more particularly, to an auxiliary handle for such a tool.
Portable electric drills are typically configured with a pistol grip toward the rear end, by means of which the operator can use one hand to hold, manipulate and control the operation of the drill. It is often desirable to provide a secondary, or auxiliary, handle toward the forward end of the drill to effect two-handed operation. This is frequently the case with larger drills which are often awkward and unbalanced when used in a one-handed manner.
A common way in the past of providing such an auxiliary handle was to have internally threaded blind holes provided in the body of the drill at one or more locations near the forward end of the drill and providing an auxiliary handle having a threaded end for selective insertion into one of the holes. This arrangement is disadvantageous in that, for example, only a very limited number of angular orientations of the handle around the drilling axis of the drill may be accommodated. Also, additional machining of the drill is required.
Arrangements are also known whereby an auxiliary handle may be mounted on a cylindrical portion of the drill housing and for rotation to any desired angle within a 360.degree. range. An example of such an arrangement is disclosed in U.S. Pat. No. 3,537,336. However, that disclosed arrangement is disadvantageous in that there are numerous parts which increases its cost of manufacture. Another such arrangement is disclosed in U.S. Pat. No. 4,881,294, which suffers from the same disadvantages. A third arrangement is disclosed in U.S. Pat. No. 4,820,090, but this arrangement lacks means for locking the auxiliary handle at a desired angular orientation.
It is therefore a primary object of the present invention to provide an auxiliary handle for a drill which is simple to manufacture and use and which avoids the disadvantages enumerated above.
It is another object of this invention to provide such a handle which includes the provision for holding a depth stop.